马氏体轴承钢碳氮共渗滚动接触疲劳失效机理  

Rolling Contact Fatigue Failure Mechanism of Martensitic Bearing Steel after Carbonitriding

作　　者：蒋港辉 李淑欣 蒲吉斌[2] 王海新[2] 陈银军 JIANG Ganghui;LI Shuxin;PU Jibin;WANG Haixin;CHEN Yinjun(School of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 315211,China;Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China;Huanchi Bearing Group Limited Company,Cixi 315318,China)

机构地区：[1]宁波大学机械工程与力学学院,宁波315211 [2]中国科学院宁波材料技术与工程研究所,宁波315201 [3]中国环驰轴承集团有限公司,慈溪315318

出　　处：《中国表面工程》2022年第2期12-23,共12页China Surface Engineering

基　　金：国家自然科学基金(52075271);国家重点研发计划(2018YFB2000300)资助项目。

摘　　要：碳氮共渗工艺应用广泛,但对碳氮共渗后零部件的滚动接触疲劳失效机理研究较少。采用气体碳氮共渗对马氏体轴承钢进行表面改性处理,对碳氮共渗试样进行滚动接触疲劳试验,研究碳氮共渗对轴承钢滚动接触疲劳性能的影响及其失效机理。研究结果表明:碳氮共渗试样表面硬度、残余应力和残余奥氏体含量显著提高,使得其接触疲劳寿命明显高于常规试样。疲劳裂纹萌生于表面和亚表面,其中大量表面平行裂纹主要由表面白色蚀刻层硬度梯度变化而导致,表面材料受到严重微观塑性变形产生晶粒细化;亚表面裂纹萌生位置受最大应力的分布和渗层厚度的影响。表面和亚表面疲劳裂纹的扩展和连接最终导致碳氮共渗试样出现浅层剥落和分层剥落的失效形貌。Carbonitriding is widely used,it is necessary to further reveal the rolling contact fatigue performance of modified parts.The surface of martensitic bearing steel is treated by gas carbonitriding method.Rolling contact fatigue tests are carried on carbonitrided specimens.The effect of carbonitriding on the rolling contact fatigue property and failure mechanism are studied.The results show that the carbonitrided specimens display significantly increase fatigue lives in contrast to the conventional specimens.This is due to the increase in the hardness,residual stress and content of retained austenite.Fatigue cracks of originate from both the surface and sub-surface.The parallel surface cracks are mainly caused by hardness gradient change in white etch layer.The surface is subjected to severe plastic deformation induced grain refinement.The sub-surface cracks are greatly influenced by the distribution of the maximum stress and the carbonitriding thickness.The surface and subsurface crack propagation and coalescence leads to shallow spalling and delamination.

关 键 词：碳氮共渗 马氏体轴承钢 滚动接触疲劳 失效机理 裂纹萌生 

分 类 号：TG113[金属学及工艺—物理冶金]